#include <bits/stdc++.h>

#define in read()
#define fi first
#define se second
#define pb push_back
#define rep(i, x, y) for(int i = (x); i <= (y); i++) 
#define per(i, x, y) for(int i = (x); i >= (y); i--)

using namespace std;

using ll = long long;
using db = double;
using pii = pair < int , int >;
using vec = vector < int >;
using veg = vector < pii >;

int read() {
	int x = 0; bool f = 0; char ch = getchar(); while(!isdigit(ch)) f |= ch == '-', ch = getchar(); 
	while(isdigit(ch)) x = x * 10 + (ch ^ 48), ch = getchar(); return f ? -x : x;
}

const int N = 5010;
const int mod = 998244353;

int f[N][N], s[N], n, m;

int upd(int x) { return x + (x >> 31 & mod); }

int main() {
#ifndef ONLINE_JUDGE
	freopen("1.in", "r", stdin);
#endif
	n = in, m = in;
	f[0][0] = 1;
	rep(i, 1, n) {
		rep(j, 0, n) {
			s[j % i] = upd(s[j % i] + f[i - 1][j] - mod);
			if(j - i * (m + 1) >= 0) s[j % i] = upd(s[j % i] - f[i - 1][j - i * (m + 1)]);
			f[i][j] = s[j % i];
		}
	}
	
	return 0;
}
